2015 AGRICULTURAL AND HORTICULTURAL SCIENCE

Transcription

1 External Examination AGRICULTURAL AND HORTICULTURAL SCIENCE FOR OFFICE USE ONLY SUPERVISOR CHECK ATTACH SACE REGISTRATION NUMBER LABEL TO THIS BOX RE-MARKED Tuesday 17 November: 1.30 p.m. Time: 2 hours Pages: 27 Questions: 17 Examination material: one 27-page question booklet one SACE registration number label Approved dictionaries and calculators may be used. Instructions to Students 1. You will have 10 minutes to read the paper. You must not write in your question booklet or use a calculator during this reading time but you may make notes on the scribbling paper provided. 2. This paper is in two parts: Part 1: Short-answer Questions (Questions 1 to 15) Answer all questions in the spaces provided in this question booklet. Part 2: Extended-response Questions (Questions 16 and 17) Answer either Question 16 or Question 17. Write your answer in the space provided in this question booklet. Write on page 27 if you need more space. 3. In Part 1 there is no need to fill all the space provided; clear, well-expressed answers are required. If you delete part or all of an answer, you should clearly indicate your final answer and label it with the appropriate question number. 4. The allocation of marks and the suggested allotment of time are as follows: Part marks 95 minutes Part 2 20 marks 25 minutes Total 120 marks 120 minutes 5. Attach your SACE registration number label to the box at the top of this page. SACE Board of South Australia 2015

2 STUDENT S DECLARATION ON THE USE OF CALCULATORS By signing the examination attendance roll I declare that: my calculators have been cleared of all memory no external storage media are in use on these calculators. I understand that if I do not comply with the above conditions for the use of calculators I will: be in breach of the rules have my results for the examination cancelled or amended be liable to such further penalty, whether by exclusion from future examinations or otherwise, as the SACE Board of South Australia determines. page 2 of 27

3 PART 1: SHORT-ANSWER QUESTIONS (Questions 1 to 15) (100 marks) Answer all questions in this part in the spaces provided. The allocation of marks is shown in brackets at the end of parts of each question. You should spend about 95 minutes on this part. 1. Refer to the following diagram, which shows a cross-section of a seed: B C A D Source: Adapted from J. Laffan, Cropping Systems for Sustainable Wheat Production, NSW Agriculture, Paterson, 1999, p.15, fig.1a (a) Complete the table. Label Structure Function A food storage for the seed B radicle C cotyledon D protects the seed (2 marks) (b) Explain the role of oxygen in the germination of the seed. page 3 of 27 PLEASE TURN OVER

4 2. Both monocotyledons and dicotyledons can be grown as crops. (a) Draw a dicotyledon root system and label the two types of root present. (2 marks) (b) State how this root system differs from that of a monocotyledon. (1 mark) (c) Explain one advantage of choosing a dicotyledon over a monocotyledon as a crop. (d) List two agricultural examples of dicotyledons. (1 mark) (e) Name and describe a process by which roots absorb nutrients from the soil. page 4 of 27

5 3. Horticultural production requires many management considerations in order to achieve success. Two of these are optimal provision of nutrients and successful plant propagation. (a) Two of the macronutrients that a horticulturalist would provide to plants are Ca and S. Explain the role of one of these macronutrients. Macronutrient: Role: (b) (i) Explain how tissue culture can be used to propagate plants. (2 marks) (ii) State whether tissue culture is classified as asexual or sexual reproduction. Justify your answer. (2 marks) page 5 of 27 PLEASE TURN OVER

6 4. Glucose is an important compound found in plants. (a) State the name of the process used to move glucose through a plant. (1 mark) (b) Name the chemical reaction that consumes glucose in plants. (1 mark) (c) (i) State the name of the cellular structure in which photosynthesis occurs. (1 mark) (ii) Write a chemical equation for photosynthesis. (1 mark) (d) Refer to the following graph, which shows the rate of glucose production by photosynthesis and the rate of glucose consumption in green grass: rate of glucose production or consumption (gh 1 ) glucose production glucose consumption midnight 6 a.m. noon time 6 p.m. midnight (i) Net production of glucose = glucose produced glucose consumed (1) State and explain the net production of glucose at 6 a.m. (2 marks) page 6 of 27

7 (2) Explain the change in net production of glucose between 6 a.m. and 6 p.m. (2 marks) (ii) Some horses are intolerant to carbohydrate, so their consumption of glucose must be restricted. Explain whether these horses should be grazed on grass early in the morning or around noon. (2 marks) page 7 of 27 PLEASE TURN OVER

8 5. Refer to the following graph, which shows the combined effects of rotation and fertiliser application on soil fertility: change in fertility index (%) kg ha 1 nitrogen applied 80 kg ha 1 nitrogen applied 15 sown pasture volunteer pasture beans lupins peas fallow cereal rotation (alternating with wheat) Source: Adapted from G. Taylor, K. Holden, & T. Yeatman (eds), Winter Cereal Management Guide, Department of Agriculture, SA, 1991, p. 2-7, fig. 2.4 (a) Explain the effect on soil fertility of a rotation with sown pasture compared to a rotation with cereal. (b) Explain the effect on soil fertility, when no nitrogen is applied to the soil, of a rotation with beans compared to a rotation with peas. page 8 of 27

9 (c) Explain the effect on soil fertility of a rotation with volunteer pasture compared to a rotation with fallow. 6. Farmers may choose to use ammonium fertilisers to apply nitrogen to the soil. However, when ammonium is added to soils, it is gradually converted to nitrate in the process of nitrification. Refer to the following graph, which shows the results of an investigation to test the effect of temperature on the conversion of ammonium to nitrate in soil: conversion of ammonium to nitrate (%) soil temperature (ºC) Explain why the conversion of ammonium to nitrate is low when the temperature of the soil is low. page 9 of 27 PLEASE TURN OVER

10 7. Refer to the following graph, which shows earthworm numbers at 10 cm depth after two types of tillage: 400 earthworms m conventional cultivation direct drilling 0 after pasture after lupins Source: G. Taylor, K. Holden, & T. Yeatman (eds), Winter Cereal Management Guide, Department of Agriculture, SA, 1991, p. 4-13, fig. 4.7 (a) (i) Compare the effect of conventional cultivation with that of direct drilling on earthworm numbers. (1 mark) (ii) Explain one probable reason for your answer to part (a)(i). (2 marks) (b) Explain the difference between the terms soil structure and soil texture. page 10 of 27

11 (c) (i) Explain one way that direct drilling can improve soil structure. (2 marks) (ii) Explain how this improved soil structure is beneficial to plant growth. (2 marks) 8. Often, the more nematodes there are in the soil, the lower the incidence of fungal disease in the wheat grown in the soil. Explain this relationship. page 11 of 27 PLEASE TURN OVER

12 9. Refer to the following diagram, which shows a soil profile: Source: Adapted from D.A. Macleod et al., Soils and Climate in Agricultural Production Systems, Australian Agriculture Series, Book 2, University of New England, 1984, p. 35, fig (a) On the diagram, label the soil horizons A1 and B2. (2 marks) (b) Identify the components of: (i) the A horizon. (1 mark) (ii) the B horizon. (1 mark) (c) Explain why the A2 horizon is often lighter in colour than the horizons above and below it. (2 page 12 of 27 marks)

13 (d) Explain the effect of very shallow A and B horizons (total 300 mm) on the productivity of this soil. page 13 of 27 PLEASE TURN OVER

14 10. Refer to the following graph, which shows the overall cereal yield from 1850 to 2000 in a single farming area in Australia: yield (t ha 1 ) Explain two factors related to improvements in scientific knowledge, agricultural practices, and/or technology that contributed to the change in crop yields observed from 1850 to (4 marks) page 14 of 27

15 11. Sodic soils have a large amount of sodium. A farmer can try to correct the sodicity by applying gypsum. (a) Explain how the physical structure of the soil is changed by the application of gypsum. (b) When gypsum is applied, the soil salinity sometimes increases. Explain why this occurs. (c) Explain why soil salinity is a problem in agriculture. page 15 of 27 PLEASE TURN OVER

16 12. Refer to the following diagram, which shows a monogastric digestive system: Source: Adapted from an illustration by D. Booth in L. Brown, R. Hindmarsh, & R. McGregor, Dynamic Agriculture Years 11 12, 3rd edn, Cengage Learning Australia, 2015, p. 77, fig. 5.4 (a) Write the name in the space provided, and clearly label on the diagram, the organ where: (i) physical digestion takes place (A): (1 mark) (ii) digestive acid is added (B): (1 mark) (iii) most water is absorbed (C): (1 mark) (b) Explain the significance of two structural differences between poultry and pig digestive systems. (4 marks) page 16 of 27

17 13. (a) List two common ruminant animals found in agricultural production in southern Australia. (1 mark) (b) (i) Name the four chambers of a ruminant stomach. (2 marks) (ii) Describe the function of: (1) the second chamber. (1 mark) (2) the third chamber. (1 mark) (c) Monogastric animals that are fed mainly grains are able to digest and absorb carbohydrates very efficiently. Explain one reason why ruminant animals cannot digest grains as efficiently as monogastric animals. (d) Ruminant animals that have been grazed on pasture are slowly introduced to high-grain feeds when they are moved to feedlots. Explain what happens in the ruminant stomach that improves its ability to digest grains. page 17 of 27 PLEASE TURN OVER

18 14. Sheep breeds have markedly different optimal breeding seasons. Merino breeds generally ovulate from November to July, while British breeds usually ovulate from February to May. A sheep oestrous cycle is typically 16½ days long; gestation is 150 days. (a) Describe ovulation. (1 mark) (b) Name the hormone that causes ovulation. (1 mark) (c) Suggest one reason why different breeds have optimal breeding seasons of different lengths. (1 mark) (d) (i) Explain one reason why a teaser ram might be kept with a flock of ewes prior to joining. (2 marks) (ii) Explain how a wether can be used as a teaser. (2 marks) page 18 of 27

19 (e) Rams are commonly joined with a flock of ewes for an 8-week period. (i) Suggest one reason why rams are left with ewes for this length of time. (1 mark) (ii) State two consecutive months when rams could be joined with Border Leicester ewes. (1 mark) (iii) Based on the joining period identified in your answer to part (e)(ii), predict when lambing should begin. (1 mark) page 19 of 27 PLEASE TURN OVER

20 15. Refer to the following table, which lists the daily metabolisable energy (ME) and nutrient requirements of breeding cattle: Live weight (kg) ME (MJ) Daily requirements Protein (g) Calcium (g) Phosphorus (g) Pregnant heifers last third of pregnancy Dry pregnant mature cow last third of pregnancy Lactating heifers first 3 4 months post-calving Lactating mature cows first 3 4 months post-calving Source: Adapted from Nutrient Requirements of Beef Cattle, 6th revised edition, 1984, (a) Refer to the following table, which shows the ME and nutrients provided by two cattle feed mixes: Component Mix A Mix B ME (MJ) Protein (kg) Calcium (kg) (i) Identify which feed mix is most suitable for a pregnant heifer. (1 mark) (ii) Name two common grains that could be the source of the ME provided by this feed mix. (1 mark) page 20 of 27

21 (iii) (1) State one reason why the energy requirement of a pregnant heifer is different from that of a non-lactating pregnant cow. (1 mark) (2) State one reason why the energy requirement of a pregnant heifer is different from that of a lactating mature cow. (1 mark) (b) State the energy and protein requirements of heifers that weigh 400 kg after parturition. After parturition ME (MJ) Protein (g) (2 marks) (c) The daily requirement of phosphorus is listed in the table. State two functions of phosphorus in an animal. (d) State why lactating heifers and lactating cows have a high daily requirement of calcium. (1 mark) page 21 of 27 PLEASE TURN OVER

22 PART 2: EXTENDED-RESPONSE QUESTIONS (Questions 16 and 17) (20 marks) Answer either Question 16 or Question 17. Write your answer on the following pages, clearly labelling it with the number of the question you choose. You should spend about 25 minutes on this section. Credit will be given for clear, well-expressed answers that are well organised and relevant to the question. 16. Agricultural chemicals, in all of their different forms, play a vital role in the high productivity of the agricultural and horticultural industries of Australia. Their use, however, is closely monitored for negative impacts from incorrect or careless usage and disposal. At times, alternatives to chemicals are more appropriate. Using two examples, describe how plant hormones are used to increase agricultural and horticultural production. Explain one possible effect on soil ph of over-fertilising a crop, and the consequent effect on soil fertility. Discuss two possible effects of overusing antibiotics in intensive animal enterprises: one on animal husbandry and one on consumer perception. Describe two different control methods for minimising production losses caused by invertebrates or micro-organisms: one during production and one during storage of products. 17. Some micro-organisms and invertebrates play important roles in the high productivity of the agricultural and horticultural industries of Australia. Others, however, can cause serious problems for these industries. Describe the physical characteristics of one invertebrate and one micro-organism that are important in agricultural and horticultural production. Explain the importance of one invertebrate in horticultural production and one micro-organism in broadacre agricultural production. Describe the role of one invertebrate that causes food spoilage and one micro-organism that is used in food or beverage production. Discuss two roles of biosecurity in protecting both the agricultural and the food industries. page 22 of 27

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27 You may write on this page if you need more space to finish your answers to any questions. Make sure to label each answer carefully (e.g. Question 16 continued ). page 27 of 27 end of question booklet

28 AGRICULTURURAL AND HORTICULTURAL SCIENCE 2015 ACKNOWLEDGMENT Question 15, page 20, source: State of Queensland, Department of Agriculture and Fisheries, Creative Commons Attribution 3.0 licence The SACE Board of South Australia has made every effort to trace copyright holders. If however, any material has been incorrectly acknowledged, we apologise and invite the copyright holder to contact us.